NVMe: Add revalidate_disk callback

This adds a callback to revalidate the disk and change its block size
and capacity if needed. Before, a user would have to remove + rescan
an entire device if they changed the logical block size using an NVMe
Format or other vendor specific command; now they can just run something
that issues the BLKRRPART IOCTL, like

 # hdparm -z /dev/nvmeXnY

This can also be used in response to the 1.2 Spec's Namespace Attribute
Change asynchronous event.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 16a886c2b73d..93ee55ee3775 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1853,6 +1853,35 @@ static int nvme_getgeo(struct block_device *bd, struct hd_geometry *geo)
         return 0;
 }
 
+static int nvme_revalidate_disk(struct gendisk *disk)
+{
+        struct nvme_ns *ns = disk->private_data;
+        struct nvme_dev *dev = ns->dev;
+        struct nvme_id_ns *id;
+        dma_addr_t dma_addr;
+        int lbaf;
+
+        id = dma_alloc_coherent(&dev->pci_dev->dev, 4096, &dma_addr,
+                                                                GFP_KERNEL);
+        if (!id) {
+                dev_warn(&dev->pci_dev->dev, "%s: Memory alocation failure\n",
+                                                                __func__);
+                return 0;
+        }
+
+        if (nvme_identify(dev, ns->ns_id, 0, dma_addr))
+                goto free;
+
+        lbaf = id->flbas & 0xf;
+        ns->lba_shift = id->lbaf[lbaf].ds;
+
+        blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
+        set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
+ free:
+        dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
+        return 0;
+}
+
 static const struct block_device_operations nvme_fops = {
         .owner          = THIS_MODULE,
         .ioctl          = nvme_ioctl,
@@ -1860,6 +1889,7 @@ static const struct block_device_operations nvme_fops = {
         .open           = nvme_open,
         .release        = nvme_release,
         .getgeo         = nvme_getgeo,
+        .revalidate_disk= nvme_revalidate_disk,
 };
 
 static void nvme_resubmit_iods(struct nvme_queue *nvmeq)